The frame is held in place by two bolts visible above the door hinges when you open the doors. It may just be the decorative cover coming loose on yours though.
there is no bottom frame. the rubber seal fits in a lip on the body itself. The "chrome" piece is a cosmetic stainless steel piece that fits in the rubber seal. It looks like it is pulling away from the frame along with the rubber. This is a split piece with a coupler in the middle. You may be able to work it back to the frame.
So I've been looking at this the past couple of days and I found the bolts that hold the windshield frame on. Those are solid and the "vertical" frame bits are solid.
The lower chrome trim is cosmetic, as you guys said, but isn't it also somewhat holding the glass itself in place? I've tried working it back up, but it's quite tight and doesn't want to budge.